public override void Parse(TreeBuilder tree)
{
S2K = new S2K();
Version = tree.ReadByte("Version");
S2K.SymAlgo = tree.ReadByte("Symmetric Algorithm", SymmetricAlgorithmTypes.Get);
byte S2KSpecifier = tree.ReadByte("S2K Specifier", S2KTypes.Get);
if (S2KSpecifier != S2KTypes.Salted && S2KSpecifier != S2KTypes.Simple && S2KSpecifier != S2KTypes.IteratedAndSalted)
{
throw new InvalidDataException("Invalid S2K Specifier");
}
S2K.HashAlgorithm = tree.ReadByte("Hash Algorithm", HashAlgorithmTypes.Get);
if (S2KSpecifier == S2KTypes.Salted || S2KSpecifier == S2KTypes.IteratedAndSalted)
{
S2K.Salt = tree.ReadBytes("Salt", 8);
if (S2KSpecifier == S2KTypes.IteratedAndSalted)
{
byte CodedCount = tree.ReadByte("Coded Iteration");
S2K.ByteCount = (16 + (CodedCount & 15)) << ((CodedCount >> 4) + 6);
}
}
if (tree.IsMoreData())
{
EncryptedSessionKey = tree.ReadBytes("Encrypted Session Key");
}
else
{
EncryptedSessionKey = null;
}
}
public bool DecryptS2K(string Password)
{
byte[] SessionKey = S2K.GetKey(Password);
var decryptor = SymmProcess.GetDecryptor(S2K, SessionKey);
var BlockSizeBytes = S2K.IV.Length;
int EncryptedLength = EncryptedPrivateKey.Length;
int BlockFillLength = BlockSizeBytes * ((EncryptedLength / BlockSizeBytes) + 1);
byte[] CryptBytes = new byte[BlockFillLength];
Array.Copy(EncryptedPrivateKey, 0, CryptBytes, 0, EncryptedLength);
byte[] ClearBytes;
using (MemoryStream msDecrypt = new MemoryStream())
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Write))
{
csDecrypt.Write(CryptBytes, 0, CryptBytes.Length);
csDecrypt.Close();
}
ClearBytes = msDecrypt.ToArray().SubArray(0, EncryptedLength);
}
// Validate Decrypted Key
int CheckLen = (S2K.S2KUsage == 254) ? 20 : 2;
int DataLen = ClearBytes.Length - CheckLen;
byte[] CheckSum = ClearBytes.SubArray(DataLen, CheckLen);
bool bSuccess;
if (CheckLen == 2)
{
long C = 0;
for (int i = 0; i < DataLen; i++)
{
C += ClearBytes[i];
}
C = C % 65536;
bSuccess = ((C >> 8) == CheckSum[0] && (C & 0xff) == CheckSum[1]);
}
else
{
SHA1Managed sha = new SHA1Managed();
byte[] HashToCompare = sha.ComputeHash(ClearBytes.SubArray(0, DataLen));
bSuccess = HashToCompare.SequenceEqual(CheckSum);
}
if (bSuccess)
{
return(SetPrivate(ClearBytes));
}
return(false);
}
public static ICryptoTransform GetDecryptor(S2K S2k, byte[] SessionKey)
{
return(GetDecryptor(S2k.SymAlgo, S2k.IV, SessionKey));
//if (S2k.SymAlgo != SymmetricAlgorithmTypes.AES128)
// throw new NotImplementedException("Non AES128 not yet implemented");
//int KeySize = SymmetricAlgorithmTypes.GetKeySize(S2k.SymAlgo);
//int BlockSizeBytes = S2k.IV.Length;
//RijndaelManaged aes = new RijndaelManaged
//{
// KeySize = KeySize,
// BlockSize = BlockSizeBytes * 8,
// FeedbackSize = BlockSizeBytes * 8,
// Key = SessionKey,
// IV = S2k.IV,
// Mode = CipherMode.CFB,
// Padding = PaddingMode.None
//};
//return aes.CreateDecryptor();
}
public override void Parse(TreeBuilder tree)
{
base.Parse(tree);
bool IsEncrypted = true;
tree.SetBookMark();
var S2K = new S2K
{
S2KUsage = tree.ReadByte()
};
if (S2K.S2KUsage == 254 || S2K.S2KUsage == 255)
{
S2K.SymAlgo = tree.ReadByte("Symmetric Algorithm", SymmetricAlgorithmTypes.Get);
byte S2KSpecifier = tree.ReadByte("S2K Specifier", S2KTypes.Get);
if (S2KSpecifier != S2KTypes.Salted && S2KSpecifier != S2KTypes.Simple && S2KSpecifier != S2KTypes.IteratedAndSalted)
{
//tree.AddCalculated("Invalid S2K", S2KSpecifier.ToString());
tree.AddCalculated("Unable to Process", S2KSpecifier.ToString(), ByteBlockType.CalculatedError);
return;
}
S2K.HashAlgorithm = tree.ReadByte("Hash Algorithm", HashAlgorithmTypes.Get);
if (S2KSpecifier == S2KTypes.Salted || S2KSpecifier == S2KTypes.IteratedAndSalted)
{
S2K.Salt = tree.ReadBytes("Salt", 8);
if (S2KSpecifier == S2KTypes.IteratedAndSalted)
{
byte CodedCount = tree.ReadByte("Coded Iteration");
S2K.ByteCount = (16 + (CodedCount & 15)) << ((CodedCount >> 4) + 6);
}
}
int BlockSizeBytes = SymmetricAlgorithmTypes.GetBlockSize(S2K.SymAlgo) / 8;
S2K.IV = tree.ReadBytes("IV", BlockSizeBytes);
}
else
{
byte SymAlgo = S2K.S2KUsage;
S2K.SymAlgo = SymAlgo;
if (SymAlgo != 0)
{
tree.GoToBookMark();
tree.ReadByte("Symmetric Algorithm", SymmetricAlgorithmTypes.Get);
int BlockSize = SymmetricAlgorithmTypes.GetBlockSize(SymAlgo) / 8;
S2K.IV = tree.ReadBytes("IV", BlockSize);
}
else
{
IsEncrypted = false;
}
}
PublicKeyAlgorithm.S2K = S2K;
if (IsEncrypted)
{
byte[] Encrypted = tree.ReadBytes("Encrypted Secret Key");
PublicKeyAlgorithm.EncryptedPrivateKey = Encrypted;
tree.CurrentBlock.ProcessBlock += ExtractPrivateKey;
SecretKeyNode = tree.CurrentBlock;
}
else
{
byte[] ClearBytes = tree.ReadBytes("Unencrypted Secret Key");
var SecBlockClear = PublicKeyAlgorithm.SetPrivate(ClearBytes);
tree.AddChild(PublicKeyAlgorithm.GetPrivateByteBlocks());
}
}
